Maker Pro
Maker Pro

How To Read Spark Time On oscilloscope With High Resistance Probe

russwr

Dec 20, 2019
32
Joined
Dec 20, 2019
Messages
32
AI computer says the engine spark on time is different (LESS) for 6000RPM as compared with idling 700 RPM. The regular Briggs mower engine Magnetron fires about .27 Milliseconds as about 10 degrees of flywheel rotation of 6000rpm. There may be confusion on my part, as regarding length of spark time, from normal Briggs Zero to continuance of spark such as to degrees to negative minus 34 degrees ATDC, and then some. Some engines start at BEFORE TDC but the Georgia AUTO engines conversions had timing start at about negative - 34 degrees ATDC PLUS the time lag due, to the 1.5MH inductor in series with the 10kv ignition. This allowed slightly more contact time of pulse current with the water at spark plug gap according to the forum tech data. (More Hydrogen formed) The high volts plasma path initiates electrolysis for the 6-7 amps,and then reduces in voltage as idling running engine. The S1R9A9M9 triple wires elecromagnet 6-7 amp coil magnetic field over the spark plug cable causes an extension of spark time, plus inductor time. This was to simulate timing as ATDC, since mower engine ignition coils are stationary, with firing start at zero, while the older car engines had adjustable distributor for any timing change and also -34 degrees to start. There was no exact data given on the Briggs spark time with the electromagnet field. The regular plug cable hooked to section of bare 5 turns copper wire under the field stress, before going to spark plug.This did cause spark time extension to some point. Oscilloscope test would be required.Their scope data was not given to us. Half wave DC Isolated power supply could possibly still be used, as they did in 2008, in conjunction with the dual inductors - as was in the original relays per cylinder. 1.5+1.5 = 3Millihenries as both together in series with low volts, and just one 1.5MH in series was with the high volts. . The assumption was that since cars used -34 degrees to start timing , then the Briggs should be in that range also, as being a 4 stroke engine.
 

Bluejets

Oct 5, 2014
6,865
Joined
Oct 5, 2014
Messages
6,865
Your figures are all (mostly) garbage along with the theory behind your explanations why.
Look for blue smoke if your idea is to connect a scope to the HT.
Blue moon must be out again I fear..........:eek:
 

kellys_eye

Jun 25, 2010
6,499
Joined
Jun 25, 2010
Messages
6,499
AI computer says
Your first mistake.....

Spark timing (duration) is constant however when the spark is initiated does indeed vary with the rpm of the engine.

There are 'scopes dedicated to use with engines and they use a pick-up coil to measure the spark and a stroboscopic light to prove the timing.

Much of the rest of your post is 'diatribe'.
 
Top